1. Field of the Invention
The present invention relates to an electronic device, and more particularly, to an electronic device in which computer system component elements such as a CPU and peripheral equipment control ICs are encased in a card-like casing.
2. Description of Related Art
In recent years, microcomputer technology has made outstanding progress. Microcomputers have been substituted for hardware to perform control functions, and thus have come to be incorporated in a variety of equipment. The equipment having such built-in computers includes automobiles, vending machines, machine tools, cash dispensers, etc. The computer systems incorporated in these equipment are designed exclusively for the equipment (for special purposes). That is, they are special purpose computers. Their applicabilities to general purposes (that is, as general purpose computers) are low. This is because an optimal configuration and a minimum size differs depending on the purpose of the application. If a general purpose computer system is adopted, the equipment, including the computer system becomes large in size.
The foregoing computer system incorporated in equipment does not usually have generality in terms of a shape and a size. Nevertheless, some computer systems preserve generality in terms of architecture. This is attributable to the fact that a specific architecture (for example, PC-AT of IBM Corp.) has been regarded as a substantial standard in this industry. As long as the architecture is adopted, a variety of peripheral equipment conformable to the architecture is available. The peripheral equipment is not limited to external storage devices such as a hard disk and communication equipment but also includes a debugger and an in-circuit emulator (ICE) for use in development.
However, even when an architecture is generalized, as mentioned above, since a shape is not generalized, it takes considerable time for development and manufacturing. This point will be clarified. In a computer system incorporated in a type of equipment, a central processing unit (hereinafter, CPU) and peripheral equipment control ICs are mounted on one or more than two printed wiring boards and then connected over printed circuits. When an attempt is made to downsize the equipment, or when priority is given to the design of an outline, since a space in which a computer system is stowed is limited, the size and shape of a printed wiring board (hereinafter, PW board) cannot help being diversified. For developing new equipment, designing and manufacturing of a new computer system, that is, designing and manufacturing of a shape of a PW board, a layout or chips, and artwork of wiring must be carried out independently. If a computer system needs a plurality of printed wiring boards, the manner in which the printed wiring board is to be segmented and connected must be determined and signals to be transferred must be defined.
Thus, development of a new product is not a simple matter. Rapidly varying needs from markets sometimes cannot be accommodated. Assuming that development of a new product is not commenced until market needs are grasped, half a year or one year elapses before a developed product actually is put on the market. Consequently, the product becomes obsolete and then dies out before long. This arises a necessity of introducing new products one after another. The costs for developing new products and updating manufacturing facilities have become quite a burden.